1. Field of the Invention
The invention relates generally to a process for dissolving cellulose from a biomass material in an Ionic Liquid medium, and more particularly to integrating the dissolution process into a process in which cellulose is regenerated, derivatized, or converted.
2. Description of the Related Art
It has been known to dissolve cellulose in Ionic Liquids. S. Fischer et al., “Inorganic molten salts as solvents for cellulose”, Cellulose 10: 227-236, 2003, discloses the use of various molten salt systems as solvent media for cellulose. Upon dissolution, cellulose can be derivatized by carboxymethylation or acetylation. The starting material is pure cellulose.
Sheldrake and Schleck, “Dicationic molten salts (ionic liquids) as re-usable media for the controlled pyrolysis of cellulose to anhydrosugars”, Green Chem 2007, pp 1044-1046, reports on low temperature pyrolysis of cellulose in ionic liquid media. The starting material is pure cellulose.
For commercially viable processes it is desirable to use lower grade sources of cellulose as the feedstock. However, lower grade cellulose sources, such as lignocellulosic biomass materials, inevitably contain minerals. These minerals can interact with the Ionic Liquid medium and change its solvent properties.
Thus, there is a need for a process in which the cellulose component of a biomass material comprising cellulose and minerals is dissolved in an Ionic Liquid medium.